Its not difficult to upgrade to the later 60 amp square back alternator. You could add about 8 feet of blue wire to make it isolated field like factory did also but... that has the potential to put more current through the same old connectors and components.
I think electric choke is typically tied to the same blue wire IGN 1 wire as everything else. If its tied to the coil side of ballast resistor it wont get 12 volts. Everything that is designed to get 12 volts will work best when it gets full 12 volts.
